Saw-sharpening machine.



a; H. ROBINSON.

SAW SHARPENING MACHINE. APPLICATION run our. 14, 1991.

928,332; Patented Jul y20, 1909.

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G. H. ROBINSON. SAW SHARPBNING MAGHINE. APPLICATION FILED OUT 14, 190'].

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Patented July 20,1909.

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H. ROBINSON. SAW SHARPENING MAGHINE. APPLICATION FILED 001214, 1907.

928,332. I Patnted July'20,1909.

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WTNESSES" I r I? i 60, flg ii E Zfiw4mwu cl W flamk/z UNITED STATESPATENT OFFICE.

GEORGE H. ROBINSON, OF SEATTLE, WASHINGTON.

SAW-SHARPENING MACHINE.

To all whom it may concern:

Be it known that I, Gsonon H. RoBINsoN, a citizen of the United Statesof America, and a resident of the city of Seattle, in the county of Kingand State of V'Vashington, have invented certain new and usefulImprovements in Saw Sharpening Machines, of which the following is aspecification.

My invention has for its primary objects the provision of an improvedmachine of the above character in which either straight edged orcircular saws can be fed in an efficient manner relatively to thegrinding means so that the teeth of the saw to be sharpened can bepresented successively for sharpening.

\Vith the above and other objects in view, to be referred to as thedescription progresses, the invention resides in the features ofconstruction, combinations and arrangement of parts hereinafterdescribed and succintly pointed out in the appended claims.

Referring now to the accompanying drawings in which like nume'als ofreference indicate like parts throughout the several views: Figure 1 isa view in top plan of my in'iprovcd saw sharpening machine. Fig. 2 is anend elovatiml thereof, parts being broken avay. Fig. 3 is a fragmentaryview in top plan with parts removed, illustrating more particularly themechanism for imparting a step by step movement to the saw. Fig. is avertical cross sectional view of the construction illustrated in Fig. 3,taken on line l4t thereof. Fig. 5 is a fragmentary end elevation of aportion of a machine and illustrating the same arranged for sharpeningcircular saws, parts being broken away. Fig. 6 is a fragmentary top planview on enlarged scale of the construction shown in Fig. 5, parts beingbroken away, and Figs. 8 and 9 are detail views.

My improved machine comprises a main frame, as 1, which can be supportedin any desired manner. I have, however, illustrated the same as having abase 2 at one side through which bolts or the like can be passed forsecuring said frame in position on a bench or the like.

Reference numeral 3 indicates a swing frame, pivoted to frame 1 by apivot 4%, for horizontal swinging, and having a dependiug threaded stud5, projecting through a curved slot 5" of frame 1, and provided on itsprojecting end portion with a nut 6 through the medium of which saidswing Specification of Letters Patent.

Application filed October 14, 1907.

Patented July 20, 1909.

Serial No. 397,437.

frame can be secured in its adjusted position. Reference numeral 7indicates a track on which the saw carriage 9 is slidably mounted, saidtrack being secured to arms 8 of a plate 8. Saw carriage 9 is providedwith a suitable saw holder 10, formed of telescoping sections, wherebyto accommodate saws of various lengths, as is apparent, the respectivesections of said holder being conveniently held from accidental movementby a screw 11. The outer end portions of the sections of holder 10 arebent at substantially right angles toward frame 1, as at 10, and one ofthe said portions 10 is further bent, as at 10", and provided with a pin12 which is fitted in an aperture in the end portion of the saw 13. Theopposite end portion of saw 13 is engaged with a pin, as shown, providedon a spring clip, 15, removably held on the adjacent end portion 10 ofthe saw holder. Saw holder 10 is supported on carriage 9 at one end by arest 16, having its lower end notched to freely straddle said carriage,and at its other end by a support 17, in the form of a clamp. Support 17is slid ably mounted in a U-shaped frame 18, fixed to outwardlyprojecting lugs 18 of carriage 9, for movement longitudinally of thecarriage, and is connected with a suitable adjusting screw 19 which whenoperated will move the saw holder on carriage 9 thereby enabling theoperator to properly aline the teeth of the saw 13 relatively to theedge of the grinding wheel.

Reference numeral 20 indicates a lock nut for securing support 17 in arigid manner after it has been adjusted.

The grinding wheel, indicated at 21, is fixed to an arbor 22, journaledin bearings provided on the frame 23.

Plate 8', see Fig. 1, is secured by screws as illustrated to theslidable bar 25, of suitable length mounted in uprights for feeding thesaw to and from grinding wheel 21, said bar in the present embodimentbeing provided at its outer end with a handle 25 Acting conjointly withthe bar 25 and operated by and during movement thereof is a pawl ormember 26 for imparting a step by step movement to the saw so that theteeth of the saw will be successively presented to the grinding wheel.Said member 26 is supported at one .end for vertical rocking andhorizontal swinging between flanged clips 27 on a depending support 28,and has its free end portion formed with a cam cc ge surface 26, adaptedto engage an abutment 29 on said swing frame, during forward movementsof bar 25 and be thereby swung on support 28 to the position indicatedin dotted lines in Fig. 3. Said member 26 is provided with dogs 30 whichduring forward movement of said member engage the teeth of a toothed bar31, secured to carriage 9, and said member 26 swinging by reason of itscam portion' 26 engaging and moving part abutment 29, effects a lateralfeeding of the carriage to bring another tooth of the saw into positionto be acted upon by the grinding wheel.

I preferably term the toothed bar or member 31 a pattern, for thespacing of the teeth thereof must correspond exactly with the spacing ofthe teeth of the saW to be sharpened, except of course, when a saw to besharpened has teeth which are exactly twice the width of the teeth ofthe pattern. The mechanism for advancing the saw step by step can beadjusted so that the dogs 30 will skip a tooth of the pattern duringeach operation of member 26 and thereby effect the proper feeding of thesaw, and the pattern is therefore removably secured to the carriage asby screws 31. A spring 32 returns the member 26 to its normal positionas bar 25 is retracted, the dogs 30 during such movement riding over thebacks of the next teeth.

Adjustable stops 33, 33 are provided on the bar 25 for limiting themovement thereof.

The under surface of the forward end of member 26 is slightly curved(see Fig. 2) and rides over a guide 34 so as to be moved upward slightlywhen approaching the end of its inward travel so as to cause thecarriage to bind slightly on its track and thereby prevent any playbetween the parts during the sharpening operation, the upward pressureof the member 26 being transmitted to said carriage by the dogs 30 andpattern 31, as is obvious. Further by this construction the dogs arepositively held against lowering, thereby preventing acci dentalslipping of the carriage. Guide 34 (see Fig. 2) which is rotatablysupported has an eccentric body portion. Wings 35 are provided on oneend of guide 34 through the medium of which the operator is enabled toturn said guide and thereby adjust the same to vary the degree of upwardmovement of the free end portion of bar 26, as will readily beunderstood.

Reference numeral 36 indicates a rest pro vided on plate 8 directly infront of the grinding wheel, on which the saw bears and slides overduring the operation of present ing new teeth to be ground. A guide 37extends over rest 36 and is adapted to engage the upper face of the sawand firmly hold the saw against rest 36 so as to prevent backwardmovement thereof. Guide 37 is .25 respectively. A threaded stud 38,fixed 'on a bracket 39, on plate 8 (see F ig. 2) projects through anapproximately centrally ar ranged opening in the said guide 37 and isprovided with a nut &O which can be adjusted to vary the pressureexerted on the saw.

Grinding wheel 21 which. has its edge formed to fit between two teethand simultaneously sharpen the rear edge of one and the forward edge ofthe other, has power transmitted to it by a chain 41 which. passes overthe sprocket wheels 42, 42 the former of which is fixed to a drive shaft43 to which power can be transmitted, as by a chain (not shown) passingover sprocket wheel 44. Sprocket wheel 42 is fixed to arbor 22. Chain 41also passes over a suitable idler a5 journaled in a swing arm 46 whichenables any slack in the chain being removed. Frame 23 is alsopreferably swingingly mounted on frame 1 so that arbor 22 can be raisedor lowered as desired.

In operation after the saw 13 has been properly secured in the holder10, and the set screw 19 adjusted to properly aline the teeth with theedge of the grinding wheel, the operator adjusts swing frame 3, suchadjustment depending on the degree of pitch to be given the teeth, thengrasping the handle 25 forces the bar 25 inwardly toward the grindingwheel until stop 33 strikes the adjacent upright 25 at which time thesaw should have been advanced into engagement with the grinding wheel.During this in ovement of the bar the member 26 has adjusted the saw aspreviously described and upon retraction of the bar 25, which isassisted by a spring a7, said member 26 is forced by spring 28 over thebacks of the next teeth of the pattern into position for presenting thenext tooth of the saw.

In the foregoing I have described the construction particularly adaptedfor sharpening band saws, meat saws and the like and I will now proceedto describe the construction as arranged for circular saws.

The track, saw carriage, plate 8 and guide 37 are removed and a support48 is ournaled vertically in an opening 48, formed in the bar 25 (seeFigs. 3 and 5), said support being provided on its upper portion with ashoulder on which saw 49 is secured as by a nut 50. Support 48 isprovided on its lower portion with a circular toothed element or pattern51 with which is engaged one of the dogs 30 of the member 26, the otherof said dogs being preferably removed when operating on a circularpattern.

The operation of the machine when provided with either the straight orcircular pattern is, in so far as moving the saw to and from thegrinding means and advancing the saw tooth by tooth, substantially thesame.

A spring 52 exerts a yielding downward pressure on the pattern andprevents backward turning thereof.

In lieu of plate 8, another plate as plate 8 having a saw rest 53, issubstituted. (See Fig. 5.)

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent of the United States, is

1. A saw sharpening machine comprising a grinding means, a carriagesupported for movement toward and from said grinding means, means onsaid carriage for holding the saw, a toothed member fixed to saidcarriage, a member pivoted to said carriage and provided with a dogengaged with said toothed-member, and means relative to which thecarriage is movable and adapted to swing the member.

2. A saw sharpening machine comprising a grinding means, a carriagemovable toward and from said grinding means, saw supporting means onsaid carriage and being movable to present the teeth of a sawsuccessively to said grinding means, a toothed-member secured to saidsaw supporting means, a member pivoted to said carriage and providedwith a dog engaged with said toothedmember to move the same, and meansrelative to which the carriage is movable and adapted to swing saidmember.

3. A saw sharpening machine comprising a grinding means, a carriagemovable toward and from said grinding means, saw supporting means onsaid carriage, a toothedmember secured to said saw supporting means,means for moving the saw supporting means pivoted to said carriage andprovided with a dog engaged with said toothed-member, means relative towhich the carriage is movable and adapted to swing the said means formoving the saw supporting means, and means for returning said means formoving the saw supporting means to its normal position upon retractionof said carriage.

4:. A saw sharpening machine comprising a grinding means, a carriagemovable toward and from said grinding means, a saw carrier supported onsaid carriage and being movable in a direction laterally of saidgrinding means, a toothed-member fixed to said saw carrier, a means formoving the saw carrier pivoted to said carriage and provided with a dogengaged with said toothed-member, means relative to which the carriageis movable and adapted to swing the means for moving the saw carrier,and means whereby the inner end portion of said means for m0ving the sawcarrier is elevated during movement of said carriage toward saidgrinding means.

5. A saw sharpening machine comprising a grinding means, a carriagesupported for movement toward and from said grinding means, a saw holderthereon and being movable independently of said carriage, atoothed-member secured to said saw holder, means for moving the sawholder pivoted to the carriage and provided with a dog in engagementwith said toothed-member, said last means having a cam portion, anabutment arranged to be engaged with said cam portion, whereby the saidlast means will be swung during movement of the said carriage, and meansfor returning said last means to its normal position.

6. A saw sharp tning machine comprising a grinding means, a carriagesupported for movement toward and from said grinding means, a saw holderon said carriage and being movable with the carriage and being supportedfor movement independently thereof, a toothed-member secured to said sawholder, means for moving the saw holder pivoted to said carriage andprovided with a dog engaged with said toothed-member, means whereby saidmeans for saw holder is swung during movement of the carriage with thedog engagedwitli said toothed-member, the under surface of the forwardportion of said means for moving the saw holder being curved, and aguide over which the forward portion of the means for moving the sawholder moves.

Signed at Seattle,VVasliingto11, this 1st day of October 1907.

GEORGE I-I. ROBINSON. Witnesses JOHN FILKINS, SARAH B, FOLEY.

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